Async command reference
An async session accepts the following options, some of which are required.
Syntax
# async [instance_options] -N pair -d ldir -r [user@host:rdir] [session_options] ...
async
can be controlled from the HSTS GUI. Canceling an
async
transfer in the GUI shuts down async
. Required command options
Naming the async session: -N pair
-N pair
is required in
async commands. The value for pair is a name that uniquely
identifies the Aspera Sync session and is visible in IBM Aspera Console.
-N pair
must follow any instance options and must precede all
session arguments. Names can use only standard alphanumeric characters, plus "_
"
and "-
" characters.Specifying filepaths and file names: ldir and rdir
ldir specifies the local directory to be synchronized and rdir specifies the remote directory to be synchronized. File paths and file names must follow these rules:
--local-mount-signature
or --remote-mount-signature
(or both if
both endpoints are on mounts and the Aspera Sync is bidirectional) to prevent Aspera Sync from deleting files on the nonmount endpoint if the mount becomes unavailable.
For instructions on creating mount signature files, see Configuring Sync endpoints.Specifying the direction of the sync: -K direction
Aspera Sync has three modes of synchronization: push
, pull
,
and bidi
.
Using continuous mode: -C
Continuous mode is supported only when the file source is Windows, Linux, or macOS. See the following table for the operating system requirements for the Sync server and client for the different Sync directions.
Continuous Sync direction | Supported Sync client OS | Supported Sync server OS |
---|---|---|
PUSH |
Linux, Windows, macOS | All |
PULL |
All | Linux, Windows, macOS |
BIDI |
Linux, Windows, macOS | Linux, Windows, macOS |
One-time synchronization is supported between all operating systems.
The following tables are complete command line options references. View an abbreviated version from the command line by running:
# async -h
For examples of async commands and output, see Examples of async commands and output.
Environment variables
If needed, you can set the following environment variables for use with
async
. The total size for environment variables depends on your operating system
and transfer session. Each environment variable value must not exceed 4096 characters.
(V4.4.3)ASPERA_LOCAL_TOKEN=
token- Set to access the docroot. When
asperanoded
starts anascp
session, it passes the token that is used in the API authorization and transfers it into the environment of the startedascp
session. Next,ascp
uses this value to gain access to the docroot associated with the API authorization.
ASPERA_SCP_COOKIE=
cookie- Set the transfer user cookie. Overridden by
--cookie
. ASPERA_SCP_LICENSE=
license_string- Set a base64-encoded Aspera license string.
ASPERA_SCP_PASS=
password- Set the transfer user password. Overridden by
-w
and--pass
. ASPERA_SCP_TOKEN=
token- Set the transfer user authorization token. Overridden by
-W
and--token
.
Instance options
-A, --version
- Display the
async
version information and license information. --apply-local-docroot
- Arranges the local
docroot
to the local directory. -D[D..]
- Log at the specified debug level. Default is 0. More Ds return more messages.
-h, --help
- Display help for command line options.
-L
log_dir,--alt-logdir=
log_dir- Log to the specified logging directory on the local host. If the directory
doesn't exist,
async
creates it for you. -q, --quiet
- Disable all output.
--watchd=
datastore:host:port[:domain]- Use asperawatchd connected to the specified Redis for the transfer session.
datastore can be
redis
orscalekv
.For example,--watchd=redis:localhost:31415
The optional
domain
argument specifies if the domain is other than the default root. For more information, see Using the Aspera Watch Service with Sync.
Session options
-a
policy,--rate-policy=
policy- Transfer with the specified rate policy.
policy
can befixed
,fair
,high
, orlow
. Default:fair
--assume-no-mods
- Assume that the directory structure was not modified. If a directory's modification time has not
changed compared to the Aspera Sync database, async in
noncontinuous mode skips scanning the directory. This option makes scanning static directory
structures faster. Use
--exclude-dirs-older-than
instead of this option. -B
rdbdir,--remote-db-dir=
rdbdir- Save the remote database to the specified directory. Similar to
-b
, but applies to the remote database. For further usage information, see The Sync database. Default: .private-asp at the root level of the synchronized directory. The directory is created if it does not exist. If<async_db_dir>
is set in aspera.conf on the server, that setting overrides the location that is specified with-B
. -b
ldbdir,--local-db-dir=
ldbdir- Use the specified local database directory. Default: .private-asp at the root level of the synchronized directory.
You can save the Aspera Sync database to a different location than the default one under the ldir specified with
-d
. This allows you to store the database away from the main data files, which is useful for performance tuning. It is also useful when-d
ldir is located on a network share volume that does not reliably support database locking. For more usage information, see The Sync database. -C
,--continuous
- Run continuous synchronization. Default: disabled.
Usage notes:
- Continuous mode is supported only when the file source is Windows or Linux. Continuous pulls can be run from any operating system if the source is Windows or Linux. Continuous push can be run only by Windows or Linux. Continuous bidi requires that both the Aspera Sync client and server are Windows or Linux.
- If a file is open, async cannot transfer the file due to sharing violations
and might ignore the file if it is closed without changes. To specify the maximum number of retries
after a sharing violation, use with
--sharing-retry-max
. To enable periodic scans that detect when an opened file was closed and is ready for transfer, use with--scan-interval
. - If you receive an
inotify
error when attempting to run continuous synchronization, see Troubleshooting continuous Sync errors.
-c
cipher,--cipher=
cipher- Encrypt file data with encryption algorithm. Aspera
supports three sizes of AES cipher keys (128, 192, and 256 bits) and supports two encryption modes,
Cipher Feedback mode (CFB) and Galois Counter Mode (GCM). The GCM mode encrypts data faster and
increases transfer speeds compared to the CFB mode, but the server must support and permit
it.
Cipher rules
The encryption cipher that you are allowed to use depends on the server configuration and the version of the client and server:
- When you request a cipher key that is shorter than the cipher key that is configured on the server, the transfer is automatically upgraded to the server configuration. For example, when the server setting is AES-192 and you request AES-128, the server enforces AES-192.
- When the server requires GCM, you must use GCM or the transfer fails.
- When you request GCM and the server is older than 3.8.1 or explicitly requires CFB, the transfer fails.
- When the server setting is
any
, you can use any encryption cipher. The only exception is when the server is 3.8.1 or older and does not support GCM mode; in this case, you cannot request GCM mode encryption. - When the server setting is
none
, you must usenone
. Transfer requests that specify an encryption cipher are refused by the server.
Cipher values
Value Description Support aes128
aes192
aes256
Use GCM or CFB encryption mode, depending on the server configuration and version (see cipher negotiation matrix). All client and server versions. aes128cfb
aes192cfb
aes256cfb
Use CFB encryption mode. Clients version 4.0.0 and newer, all server versions. aes128gcm
aes192gcm
aes256gcm
Use GCM encryption mode. Clients and servers. none
Do not encrypt data in transit. For security and to keep the file integrity, avoid the use of this setting. All client and server versions. NONE
- Do not encrypt data in transit. For security and to keep the file integrity, avoid the use of this setting.AES128
,AES192
,AES256
- Use the GCM or CFB encryption mode, depending on the server configuration and version. Supported by all client and server versions.AES128CFB
,AES192CFB
,AES256CFB
- Use the CFB encryption method. Supported by clients and servers.AES128GCM
,AES192GCM
,AES256GCM
- Use the GCM encryption mode. Supported by clients and servers.
Default:
AES128
.Client/Server Cipher negotiation
The following table shows which encryption mode is used depending on the server and client versions and settings:
Server AES-XXX-GCM
Server AES-XXX-CFB
Server AES-XXX
Server AES-XXX
Client AES-XXX-GCM
GCM Server refuses transfer GCM Server refuses transfer Client AES-XXX-CFB
Server refuses transfer CFB CFB CFB Client AES-XXX
GCM CFB CFB CFB Client AES-XXX
Server refuses transfer CFB CFB CFB --check-sshfp=
fingerprint- Compare fingerprint to the remote host key hash and fail on mismatch.
--clean-excluded
- Remove excluded directories from snap.db on both Aspera Sync
endpoints to decrease the size of snap.db. This option applies when directories
are excluded by path (
--exclude
) or by modification time (--exclude-dirs-older-than
). If the remote endpoint is running Aspera Sync older than 3.8.0, then the option is accepted (the session does not fail) but it has no effect on either endpoint. --compression=
{zlib
|none
}- Compress a file before transfer by using the specified method. Default:
none
. --cookie=
cookie- Specify a user-defined identification string to report to the Aspera Management interface.
cookie cannot contain the special characters
\r
,\n
, or\0
. --cooloff=
sec- Delay the start of the transfer. For example, if
--cooloff=5
,async
waits 5 seconds before copying a file. If--cooloff=0
transfers start immediately. The client and server use the same cooloff period. Valid range for sec: integers 0-60. Default: 3. --cooloff-max=
sec- Wait up to the specified time (in seconds) for a file to stop changing before skipping synchronization of the file. By using this option prevents a one-time sync from waiting on a constantly changing file. The file is skipped and reported as an error. Default: 0 (disabled).
--create-dir
- Create the source directory, target directory, or both if they do not exist, rather than
reporting an error and quitting. Use with
-d
and-r
. -d
ldir,--local-dir=
ldir- Synchronize the specified local directory. Use
--create-dir
to create the remote directory if it does not exist. --dedup[=mode]
- Take the specified the action when Aspera Sync detects duplicate files on the
source, even if they have different path names. Requires
-k
with a full checksum. Available modes arehardlink
,inode
(only supported for Unix-based OSes), orcopy
. Default:hardlink
.- hardlink - When two or more source files are duplicates, a hard link is
created between them on the target. This saves storage by preventing multiple copies of the same
file from accumulating on the target. The files on the target have the same inode, even if the
source files have different inodes. The target must be running a Unix-based operating system. File
metadata preservation options (
-u
and-j
) are not supported by this option. - inode - When two or more source files have matching inodes, a hard link is
created between them on the target, and the target files have matching inodes. This option is
supported only between Unix-based platforms. If
--dedup=inode
is used in a continuous sync, use thescan-interval
option. - copy - After a file is synchronized on the target, the synchronized file is
copied to the duplicate. This saves bandwidth by not transferring duplicate files. This mode is
useful when the target is Windows. File metadata preservation options (
-u
and-j
) are supported by this option.
Without the dedup option, all duplicate files are synchronized. Duplicates might still be synchronized, rather than hard linked or copied, if one of the duplicates has not yet been synchronized on the target.
- hardlink - When two or more source files are duplicates, a hard link is
created between them on the target. This saves storage by preventing multiple copies of the same
file from accumulating on the target. The files on the target have the same inode, even if the
source files have different inodes. The target must be running a Unix-based operating system. File
metadata preservation options (
--delete-before
- (V4.4.2) Schedule the deletes ahead of transfers during scans. Can't be used with
delete-delay
or--ignore-delete
options. --delete-delay
- Postpone the actual deletion of files or directories until the end of the synchronization. Use this option to prevent transfer delays that can occur when deletions are slow on the destination.
-E
file,--exclude-from=
file- Skip paths specified in the filter file. For more information on setting filters, see Filtering patterns and examples.
- --file-manifest-path=dir
-
Supplies the underlying
ascp
process with the directory in which to put TEXT manifest files. --exclude=
"pattern"- Exclude paths that match pattern. Wildcards, such as
*
and?
, are supported but rules containing them must be in double quotation marks. For example,--exclude="*.jpg"
. For more information, see Filtering patterns and examples. --exclude-dirs-older-than=
mtime- After the initial scan, do not scan directories during subsequent synchronizations if they or
their parents have a recursive modified time older than the specified value. The recursive modified
time of a directory is the most recent modification time of it or any of its children (file or
directory). Use this option to avoid rescanning directories that are known to be unchanged since the
previous synchronization, such as a monthly archive directory structure in which only the most
recent subdirectory is being modified.
mtime might be specified in any one of the following ways:
- As a positive number of seconds since
1970-01-01 00:00:00
, for Unix and POSIX-compliant operating systems.Note: Some file servers, such as Windows NT, use a different epoch for the recursive modified time. In this case, MTIME should be specified as a duration relative to present or Coordinated Universal Time (UTC) timestamp. - As a Coordinated Universal Time (UTC) timestamp with the format
YYYY-MM-DDTHH:MM:SS
, such as2015-01-01T08:00:00
. - As a duration formatted as
DDd HH:MM:SS
orWWw DDd HHh MMm SSs
. Directories whose "mtime
" is older than Now minus MTIME are not scanned. Input requirements: Leading zero fields and spaces might be omitted. The leftmost fields are optional, but fields to the right of the largest unit that is specified are required. For example, to exclude directories older than 24 hours, you might specify1d 0:0:0
,24:00:00
, or24h 00m 00s
, but not1d
.
This option does not apply to the root directory.
Note: Aspera Sync stops and returns an error if the first run of async and the next run do not use the same--exclude-dirs-older-than
option. If the first run specifies--exclude-dirs-older-than
, then the next run must use this option, too. If the first run does not include--exclude-dirs-older-than
, then the next run fails if this option is specified. - As a positive number of seconds since
-G
size,--write-block-size=
size- Use the specified block size for writing. size is an integer with units of K, M, or bytes. The maximum is 16 MB. Default: 64 KB.
-g
size,--read-block-size=
size- Set block size for reading.
size
is an integer with units of K, M, or bytes. Default: 64 MB. -H
val,--scan-intensity=
val- Scan at the set intensity.
val
can bevlow
,low
,medium
,high
, orvhigh
.vlow
minimizes system activity.vhigh
maximizes system activity by continuously scanning files without rest. Default:medium
. --host=
host- Synchronize with the remote host that is specified by hostname or IP address. If the remote host
is a cluster, enter the cluster DNS. When using
--host=
, the characters "@
" and ":
" are not treated specially in the argument to-r
or--remote-dir
. The transfer username cannot be specified as part of the remote directory filepath. Instead, it must be set with--user=
or in the environment variable$user
(on Windows,%USER%
). Allowed forms are as follows:--remote-dir user@host:/rdir # (old method) --user user --remote-dir host:/rdir --user user --host host --remote-dir /rdir --remote-dir host:/rdir # (uses $user) --host host --remote-dir /rdir # (uses $user)
The following means the same as the first three lines:
-r /rdir --user=user --host=host
For compatibility with an earlier version,
-r A:/rdir
for any single letterA
is still taken as a Windows path, not as--host A -r /rdir
. To specify a one-letter hostname A, use an explicit--host=A
. -I
file,--include-from=
file- Scan and include paths that are specified in the filter file. For more information, see Filtering patterns and examples.
-i
file,--private-key-path=
file- Authenticate with the specified SSH private key file. For information about creating a key pair, see Creating SSH keys from the command line.
--ignore-delete
- Do not copy removals to the peer. This option is used mostly with uni-directional syncs. In bidirectional sync, a deletion on one side is ignored but the next time async is run, the file is recopied from the other end. In continuous mode, the file is not recopied until either async is restarted or the file is changed (touched).
--ignore-mode
- Do not synchronize file permissions of the source to the destination. This argument is useful
when synchronizing from a Unix-like source to a Windows destination, which has different file
permission behavior than the Unix-like source ("
read only
" files cannot be deleted or modified on Windows). --ignore_remote_host_sync_name
- Do not check that the remote host being used for the current transfer matches the host that is used when the local database was created.
--include=
"pattern"- Include paths that match pattern. Wildcards, such as
*
and?
, are supported but rules containing them must be in double quotation marks. For example,--include="*.jpg"
. For more information on how to set include and exclude patterns, see Filtering patterns and examples. -j, --preserve-gid
- Preserve file owner's gid when synchronizing files between Unix-like operating systems. Requires that async is running as root. Default: disabled.
-K
direction,--direction=
direction- Transfer in the specified direction.
direction
can bepush
,pull
, orbidi
(bidirectional). Default:push
. -k
type,--checksum=
type- Calculate the specified checksum type.
type
can besha1
,md5
,sha1-sparse
,md5-sparse
, ornone
. A value ofnone
is equivalent to a size check only andasync
will not detect a change in timestamp. Default:sha1-sparse
for local storage,none
for object storage. --keep-dir-local=
dir- Move deleted files into dir. The directory must exist (it is not created by
--create-dir
), and must be outside the synchronization directory (or excluded from the sync by using--exclude
or--exclude-from
), but on the same file system. --keep-dir-remote=
dir- Move the server's deleted files into dir. The directory must exist (it is not
created by
--create-dir
), and must be outside the synchronization directory (or excluded from the sync by using--exclude
or--exclude-from
), but on the same file system. -l
rate,--target-rate=
rate- Transfer no faster than the specified maximum transfer rate. rate is an integer with units of G/g, M/m, K/k, or bps. Default: 10 Mbps.
--local-force-stat
- Force the local Aspera Sync to retrieve file information even if no changes were
detected by scanning or file system notifications. This option incurs a performance cost at the
expense of immediately detecting file changes. See also
--remote-force-stat
. --local-fs-threads=
number- Use up to the specified number of threads to do file system operations on the local computer.
Default: 1. This option is useful when the local Sync directory is in cloud storage or mounted
storage (NFS) where file system operations are slow. To set multiple threads for file system
operations on the remote computer, use
--remote-fs-threads
. --local-mount-signature=
signature file- Verify that the local file system is mounted by the existence of this file. This option
increases the time that is required to synchronize deletes. See also
--remote-mount-signature
. --local-checksum-threads=number
-
Maximum number of threads to do checksum on the local system. Default: 4.
-m
rate,--min-rate=
rate- Attempt to transfer no slower than the specified minimum transfer rate. rate is an integer with units of G/g, M/m, K/k, or bps. Default: 200 Kbps.
--mirror
- For use only with direction=push or direction=pull. When
the remote site is scanned:
- Any destination file found missing on the remote site is sent from the source.
- Any destination file that does not match the size or checksum of the source file is replaced by the file from the source.
- Any destination file or directory that does not exist on the source is deleted.
Note: This option is not compatible with: --direction=bidi, --no-scan, --remove-after-transfer, --exclude-dirs-older-than, and --ignore-delete. -N
pair,--name=
pair- Assign a name for the synchronization session. The value can contain only ASCII alphanumeric,
hyphen, and underscore characters. This value is stored in the session cookie and can be used in IBM Aspera Console to identify the transfer session. Note:
-N
must precede all session options. -n
action,--symbolic-links=
action- Handle symbolic links with the specified method, as allowed by the server. For more information
on symbolic link handling, see Symbolic link handling.
action can be:
copy
- Create or update the link at the destination (default). Not valid for Windows source or destination.skip
- Ignore the link altogether.follow
- Treat the link as if it were the file or directory it points to, so that at the destination, what was a link is now a copy of the file or directory. Functions asskip
if source is Windows.
--no-log=stats
- Suppresses the STATS and PROG log messages.
- --no-preserve-root-attrs
- Disable the preservation of attributes on the Aspera Sync root.
--no-scan
- Never scan. Use this option in a continuous async session to synchronize only
new files (files that are added to the directory after the start of the async
session) but not existing files. With
--no-scan
, Aspera Sync relies entirely on file system notifications to detect changes. As a result, if a directory is renamed after the async session starts, then the directory name is synchronized but the contents are not (because Aspera Sync does not recognize that the files were "moved
" to the renamed directory). This option cannot be used with--scan-interval
or one-time async sessions. -O
port,--udp-port=
port- Use the specified UDP port for FASP data transfer. Default: 33001.
-o
policy,--overwrite=
policy- Overwrite files according to the specified policy, which can be
always
,older
, orconflict
. Use with-K push
andpull
. Default:always
for-K push
andpull
;conflict
for-K bidi
.Note: When syncing with object storage, only file size (--checksum=none
) can be used to compare files. Thus, the use of--overwrite=always
only overwrites files whose sizes changed. If the content of a local file is different from a file with the same name in object storage but the files are the same size, the file in object storage is not overwritten. To overwrite files in this case, use--overwrite=older
.--overwrite=older
is only accurate if the user also specifies--preserve-time
(preserve timestamps).To resolve
conflict
anderror
situations in a uni-directional sync, “touch” the problem files on the source and run async with--overwrite=always
. This clears allconflict
anderror
states as the problem files are synchronized. -P
port,--tcp-port=
port- Use the specified TCP port for SSH. port must be a valid numeric IP port. Default: 22.
--pending-max=
N- Allow the maximum number of files that are pending transfer to be no more than the specified number. This option acts as a buffer. Default: 2000.
--preserve-access-time
- Preserve file access time from the source to the destination. For IBM Spectrum Scale clusters, use to preserve the expiration time of immutable files. Default: disabled.
--preserve-acls={native|metafile|none}
- Preserve Access Control Lists (ACL) data for macOS, Windows, and AIX files. To preserve ACL data
for other operating systems, use
--preserve-xattrs
. See also --remote-preserve-acls.native
- Preserve attributes by using the native capabilities of the file system. This mode is only supported for Windows, macOS, and AIX. If the destination and source do not support the same native ACL format, async reports and error and exits.metafile
- Preserve file attributes in a separate file, named filename.aspera-meta. For example, attributes for readme.txt are preserved in a second file named readme.txt.aspera-meta. These metafiles are platform independent and can be copied between hosts without loss of information. This mode is supported on all file systems.none
- (Default) Do not preserve attributes. This mode is supported on all file systems.
Important Usage Information:
- This feature is only meaningful if both hosts are in a common security domain. If a SID (security ID) in a source file does not exist at a destination, the synchronization proceeds but no ACL data is saved, and the log records that the ACL might not be applied.
- Both --preserve-acls and --remote-preserve-acls must be specified in order for the target side of a pull to apply the ACLs.
- On Windows, the ACLs that are created for files that are transferred into user directories might restrict file access to specific users. Ensure that the ACLs on the transfer-cache directory (destination_path/session_name) are generic enough to allow access to all users who require it. For more information about the transfer-cache directory, see The Sync database.
--preserve-creation-time
- Preserve file creation time from the source to the destination. Valid only on Windows computers. Default: disabled.
--preserve-modification-time
- Preserve file modification time from the source to the destination. Default: disabled.
--preserve-object-lock-legal-hold
and
--preserve-object-lock-retention
are available only for connections from S3 to S3
storage. Also, these options are only available when using libpvcl_cloud
, but are
not available when using trapd
.--preserve-object-lock-legal-hold
- Preserve legal hold status of source files and directories when created at the destination.
--preserve-object-lock-retention
- Preserve retention information of source files and directories when created at the destination.
--preserve-time
- Preserve file timestamps. This is equivalent to
--preserve-modification-time
for Unix-based operating systems, and to--preserve-modification-time --preserve-creation-time
on Windows. Default: disabled. Same as-t
. --preserve-xattrs={native|metafile|none}
- Preserve extended file attributes data (xattr). See also
--remote-preserve-xattrs
.native
- Preserve attributes by using the native capabilities of the file system. This mode is supported only on macOS and Linux. If the destination and source do not support the same native xattr format, async reports and error and exits. If the Linux user is not root, some attributes such as system group might not be preserved.metafile
- Preserve file attributes in a separate file, named filename.aspera-meta. For example, attributes for readme.txt are preserved in a second file named readme.txt.aspera-meta. These metafiles are platform independent and can be copied between hosts without loss of information. This mode is supported on all file systems.none
- (Default) Do not preserve attributes. This mode is supported on all file systems.
Important Usage Information:
- Xattr are not preserved for directories.
- If Aspera Sync is run by a regular user, only user-level attributes are preserved. If run as superuser, all attributes are preserved.
- Use
--preserve-xattrs=native
to preserve IBM Spectrum Scale ACLs between clusters. For more information, see Preserving IBM Spectrum Scale ACLs of transferred files.
--proxy
proxy_url- Synchronize by using the specified IBM Aspera Proxy address. The Proxy URL is specified with the following
syntax:
dnat[s]://proxy_username:proxy_password@proxy_ip_address[:port]
The default port for DNAT is 9091, and for DNATS is 9092. The Proxy password must be specified or the synchronization fails to connect to the Proxy server.
-R
rem_log_dir,--remote-logdir=
rem_log_dir- Use the specified logging directory on the remote host. The directory is created if it does not
exist. If
<async_log_dir>
is set in aspera.conf on the server, async initially logs to rem_log_dir but is then redirected to the directory specified for<async_log_dir>
.Note:-R
cannot be used if the transfer user is restricted to aspshell. -r
rdir,--remote-dir=
rdir- Synchronize the specified directory on the remote host. rdir is
[[user@]host:]path. If the target is the
remote directory, you can use
--create-dir
to create the remote directory if it does not exist.CAUTION:If the source and target directories are both on the local host, do not specify a target directory that is inside your source directory. - --raw-options
- Pass arbitrary arguments to
ascp
.ascp
receives the options in the same order that they were specified.For example, to pass
"-L /tmp"
, the options are--raw-options "-L" --raw-options "/tmp"
. --remote-force-stat
- Force the remote Aspera Sync to retrieve file information even if no changes were
detected by scanning or file system notifications. This option incurs a performance cost at the
expense of immediately detecting file changes. See also
--local-force-stat
. --remote-fs-threads=
number- Use up to the specified number of threads to do file system operations on the remote computer.
Default: 1. This option is useful when the remote Sync directory is in cloud storage or mounted
storage (NFS) where file system operations are slow. To set multiple threads for file system
operations on the local computer, use
--local-fs-threads
. --remote-mount-signature=
signature file- Verify that the remote file system is mounted by the existence of this file. This option increases the time that is required to synchronize deletes.
--remote-preserve-acls={native|metafile|none}
- Like
--preserve-acls
but used when ACLs are stored in a different format on the remote computer. Defaults to the value of--preserve-acls
.Note: Both --preserve-acls and --remote-preserve-acls must be specified in order for the target side of the pull to apply the ACLs. --remote-preserve-xattrs={native|metafile|none}
- Like
--preserve-xattrs
but used attributes are stored in a different format on the remote computer. Defaults to the value of--preserve-xattrs
. --remote-scan-interval=
duration- Set the scanning interval of the remote computer. See also
--scan-interval
. --remote-scan-threads=
N- Use the specified number of directory scanning threads on the remote computer. More threads
decrease the time that it takes for async to scan the directory after the initial
synchronization, and increase the number of pending files. Default: 1. To specify the number of
scanning threads on the local computer, see
--scan-threads
. --remove-after-transfer
- Remove source files after they are successfully synchronized.
--remote-checksum-threads=number
-
Maximum number of threads to do checksum on the remote system. Default: 4.
--resume-age-days=
DAYS-
Resume the transfer if the timestamp of the file partially transferred file is less than this number of days. If the timestamp is greater or equal to the number of days, transfer the file without resuming. Default: 5.
--scan-dir-rename
- Enable the detection of renamed directories and files compared to the previous scan that is
based on matching inodes. Enable the detection of renamed directories and files compared to the
previous scan, based on matching inodes. When a new directory is found on the source and its inode
matches that of a previously found directory, it is considered a "rename" and the target directory
is renamed. The source directory is scanned for content changes, and the target directory is
updated.
Usage note:
- This option can be used only on file systems with persistent inodes, and does not work if inodes are volatile, as is the case with many network-mounted file systems.
--scan-file-rename
- Enable the detection of renamed files compared to the previous scan, based on matching inodes.
If a new file is found and its inode and last-modified time matches that of a previously found file
that does not have multiple hard links, it is considered a "
rename
" and the remote file is renamed.Usage note:
- This option can be used only on file systems with persistent inodes, and does not work if inodes are volatile, as is the case with many network-mounted file systems.
- If
--scan-file-rename
is used without--scan-dir-rename
, a directory rename causes async to create a new directory and rename its files individually.
--scan-interval=
duration- Enable periodic scans during a continuous Aspera Sync (a session run with the
-C
option) on the local host. duration is the interval between periodic scans and can be specified asDDd HH:MM:SS.mmm
orWWw DDd HHh MMm SSs XXms XXus
. Leading zero fields can be omitted. Spaces can be omitted. A plain numberXX
is interpreted asSSs
(seconds). --scan-threads=
N- Use the specified number of directory scanning threads on the local computer. More threads
decrease the time that it takes for async to scan the directory after the initial
synchronization, and increase the number of pending files. Default: 1. To specify the number of
scanning threads on the remote computer, see
--remote-scan-threads
. --sharing-retry-max=
N- Retry synchronizations up to the specified maximum number after a sharing violation. The
interval between retries is the number of seconds specified by
--cooloff
. Default: 3. --store-metadata-records
- (V4.4.2) Store
acls/xattrs
in the snapshot database. Use to audit or analyze the contents of the attributes. --symbolic-links=
action- See
-n
. --support-resume[=SIZE]
-
Only resume files that are greater than this value. Default: 1048576 (1 MB).
-t
- Preserve file timestamps. Same as
--preserve-time
. --tags=
string- User-defined metadata tags in JSON format that can be used in transfer session reporting and searches.
--tags64=
string- User-defined metadata tags in JSON format and base64-encoded that can be used in transfer session reporting and searches.
--transfer-threads=
N[:size]- Use the specified number of dedicated transfer threads and optionally specify the file size
at which files are assigned groups of threads. The number of threads must not exceed the number of
available CPU cores (the lower value of the client and server computers). If no size is specified,
infinity is used as an upper bound.
For example, to use two transfer threads to transfer files smaller than or equal to 128 bytes and six transfer threads for all other files (those larger than 128 bytes), use the following options:
--transfer-threads=2:128 --transfer-threads=6
-u, --preserve-uid
- Preserve the file owner's uid when synchronizing files between Unix-like operating systems. async must be run as root to use this option. Default: disabled.
--user=
user- Authenticate the transfer with the specified username. With this option, the characters "@" and
":" are not treated specially in the argument to
-r
or--remote-dir
. -W
token_string,--token=
token_string- Use the specified authorization token. The token type (sync-push, sync-pull, or sync-bidi) must match the direction (push, pull, or bidi) of the requested transfer. The token path must match the remote directory of the requested transfer. If an invalid token is provided, the requested transfer is denied.
-w
pass,--pass=
pass- Authenticate the transfer with the specified password.
--write-uid=
uid--write-gid=
gid- Write files as the user uid or the group gid.
uid and gid can be numeric, or by name. If by name, the name
is looked up on the host performing the write. Failure to set the uid or
gid is logged, but is not an error. The uid or
gid is set after
ascp
completes and before moving the file from the staging directory to the final location.--write-uid
conflicts with--preserve-uid
, and--write-gid
conflicts with--preserve-gid
. -X
size,--rexmsg-size=
size- Use the specified size (in bytes) for a retransmission request. Maximum: 1440.
-x, --reset
- Clear the Aspera Sync database and rescan the synchronized directories and files to create a fresh database. Default: off.
-Z
mtu,--datagram-size=
mtu- Use the specified datagram size. Value is an integer. Default: detected-path MTU.